A programmable execution service (“PES”) can provide computing resources for executing applications on a permanent or an as-needed basis. The computing resources provided by a PES may include various types of resources, such as data processing resources, data storage resources, data communication resources, and the like. Each type of computing resource may be general-purpose or may be available in a number of specific configurations. For example, data processing resources may be available as virtual machine instances (“instances”). The instances may be configured to execute applications, including World Wide Web (“Web”) servers, application servers, media servers, database servers, and the like. Data storage resources may include file storage devices, block storage devices, and the like. Customers of a PES can typically purchase and utilize the computing resources provided by the PES according to various financial models.
When a customer of a PES requests to launch a new virtual machine instance, the PES typically identifies a “slot” for executing the new instance. The selection of a slot for executing the new instance might include identifying an appropriate server computer in an appropriate data center upon which the new instance should be executed. All execution slots are not the same, however. Consequently, the selection of a particular slot for executing certain virtual machine instances might cost the operator of the PES money, rather than providing an economic benefit to the operator of the PES. For instance, certain types of virtual machine instances might have associated licensing fees that require payment for an entire month even if the virtual machine instance is only executed for a portion of the month. In this case, launching a new instance on such a virtual machine for a customer might actually cost the operator of the PES more than the revenue generated by the execution of the virtual machine instance.
It is with respect to these and other considerations that the disclosure made herein is presented.